service_worker.ts

/**
 * @license
 * Copyright 2018 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import {githubToColabUrl} from './parse';

// Details for calls to chrome.action.setPopup; see
// https://developer.chrome.com/docs/extensions/reference/api/action#method-setPopup.
const EMPTY_POPUP = {
  popup: ''
};
const HELP_POPUP = {
  popup: 'help.html'
};

// This listener is called when the user clicks the extension icon.
//
// If the current URL matches a Jupyter notebook hosted on github.com or on
// gist.github.com, this function will open a new tab and load the notebook into
// Colab.
chrome.action.onClicked.addListener(async (tab: chrome.tabs.Tab) => {
  if (!tab.url) {
    console.warn('Open in Colab was invoked without a URL.');
    return;
  }
  const colabUrl = githubToColabUrl(tab.url);
  if (!colabUrl) {
    // Set and show a helpful popup page when the extension icon is clicked on
    // an invalid URL, then unset it in case the next click is valid.
    await chrome.action.setPopup(HELP_POPUP);
    await chrome.action.openPopup();
    await chrome.action.setPopup(EMPTY_POPUP);
    console.warn(`Current page (${
        tab.url}) is not recognized as a GitHub-hosted notebook.`);
    return;
  }
  await chrome.tabs.create({'url': colabUrl});
});